A future competitive power in a vehicle market may be changed depending on a development of an environment-friendly vehicle as environmental regulations become strict. With interests in the environment-friendly vehicle growing since the 1990s, vehicles named hybrid cars have been developed and have become available commercially.
The hybrid car is a complex vehicle which has an internal combustion engine and an electric motor as like a meaning of the word hybrid, which means “mixed breed” or “mixed blood”. A low speed driving of the hybrid car is performed by the electric motor until the hybrid car increases its velocity up to a desirable velocity after starting, at which point the internal combustion engine operates primarily and the electric motor operates as an auxiliary power so as to increase speed during acceleration of the hybrid car. During a reduction of the velocity of the hybrid car, a generator is operated by inertial force so that kinetic energy of the hybrid car is converted info electric energy and stored in a battery. On the other hand, electric vehicles have been developed in which an electric power charged in batteries operates one or more electric motors so that the electric vehicles can be driven.
The batteries mounted on the hybrid cars and the electric cars as described above are charged by electricity generated through electrolysis of a positive electrode and a negative electrode. That is, the batteries are secondary Lithium ion batteries in which two electrodes of a positive electrode (copper) and a negative electrode (aluminum) are spaced apart from each other in a state of being submerged in a solution including positive ions and negative ions.
The positive electrode and the negative electrode constituting the battery of the electric vehicle are received in a housing (can) of the battery, which are respectively welded by a laser to terminals which are fixed by screws to a cap plate for isolating an opening portion of the housing of the battery. At this time, the terminals have a connection end, to which the positive electrode is fitted and fixed, integrally formed at a side thereof, and a screw portion, which is combined with a nut and fixed to the housing while providing an end connected to an external electric wire, at the other side thereof, respectively. The battery terminal as described above is assembled with a separate battery terminal plate. In a method of manufacturing a conventional battery terminal plate, a material to be processed and to have a volume is shifted to several press machines while being processed through several pressing processes to be formed with a basic shape. Then, unnecessary portions of the material are cut off, and a surface of the material is processed. The manufacturing of the battery terminal plate is then finished.
However, in the conventional method of manufacturing, there is a problem in that a shifting path of the material to be processed becomes longer and productivity of a battery terminal plate is deteriorated since the material to be processed is shifted to several pressing machines and processed. Further, in a case of the conventional pressing process, there are problems in that scraps which are metal fragments generated when a metal product is manufactured from a material to be processed or which are wastes of a metal product highly increase, and especially a fractured surface or a broken line is generated. In a case where a material to be processed has a large volume itself, the material is overflowed from the press machine and generates unnecessary scraps. In order to remove the scraps, a step of cutting the scraps through a separate barreling process (stones, water and a product in which unnecessary burrs on surfaces of the product are intended to be cut are put into a hexagonal barrel all together, and the barrel is rotated at a high speed so as to cut the unnecessary burrs) and a step of cleaning and smoothly finishing surfaces of the product must be perforated. Therefore, there is a disadvantage in that it takes a long time to perform a manufacturing process so that a manufacturing time and a manufacturing cost increase.
Especially, where an opening is formed in a material by punching the material according to the conventional art, there is a problem in that the above-mentioned fractured surface or broken line is always formed. Moreover, the battery terminal plates manufactured by the conventional method of manufacturing the battery terminal plate have irregular sizes and rough surfaces, thereby causing incomplete surface coating. Therefore, if a battery part is connected or fixed to the battery terminal plate, it has an effect on a product property, so as to deteriorate the quality of product, and causing an increase of friction.